Fernando Alonso topped the times for Aston Martin ahead of Ferrari's Charles Leclerc and Red Bull's world champion Max Verstappen in opening practice for the Singapore Grand Prix on Friday. Championship leader Oscar Piastri and his McLaren teammate Lando Norris managed only the fifth and sixth quickest times in the session behind the other Ferrari of Lewis Hamilton.
Spanish veteran Alonso, winner of the first Formula 1 race in Singapore in 2008, put in consistently fast times over the session and his best lap of 01:31.116 seconds put him top of the time sheets for good.
Leclerc, who has twice started on pole position at the Marina Bay circuit but never won a race in Singapore, was just behind the 44-year-old in with a 01:31.266.
Dutchman Verstappen, who had modest hopes of success in Singapore despite winning the last two rounds of the championship to revive hopes of a fifth straight world title, posted a best time of 01:31.392. He trails Australian Piastri by 69 points in the drivers' standings and will be looking to cut further into that deficit this weekend.
Piastri, who had a race to forget last time out in Azerbaijan, complained of understeer on one lap and clipped a wall on another but still managed a better time (01:31.481) than Norris (01:31.698), who won from pole in Singapore last year.
Racing Bulls driver Isack Hadjar was seventh fastest ahead of Carlos Sainz, who won in Singapore for Ferrari in 2023 and put his Williams on the podium two weeks ago in Baku.
Mercedes drivers George Russell and Kimi Antonelli managed only the 11th and 14th fastest times but, like Sainz, they elected not to run on the quicker soft tyres.
Despite the FIA having invoked their "heat hazard" regulation for the first time for Sunday's race, the session was conducted in relatively mild conditions by Singapore standards.
There was nothing cool about Alex Albon's session, however, as his Williams caught fire and he was forced back into the pits without recording a lap time.
Williams said the fire was caused by a "rear brake hardware problem" and were confident the Thai would be able to take part in second practice later on Friday.